A photoresist or a photoresist film is used in the manufacture of highly integrated semiconductors such as integrated circuits (IC), printed circuit boards (PCB), and/or electronic display devices, such as cathode ray tubes (CRTs), color LCD displays or organic EL displays. And, such devices are generally manufactured by using photolithography and photo-fabrication techniques.
The photoresist film requires a resolution sufficient to form a pattern with extremely fine lines and small space area of not more than 7 μm2.
The physical properties of the photoresist can be altered, such as alteration in solubility to certain solvent (that is, increase or decrease in solubility), coloration, curing and the like, via chemical modification of the molecular structure of the photoresist resin or the photoresist.
As one of conventional techniques for the formation of metal electrode, a method for manufacturing Ag electrode for PDP was featured in that a glass substrate is broadly coated with a resin composition containing silver particles dispersed therein (hereinafter, referred to as “silver paste”) by means of screen printing process, then, successively subjected to pre-baking, exposing, development, drying and calcination processes to produce the final Ag electrode.
However, since the above method developed and removed undesirable portions (that is, any part except electrode formation part) after broad application of the silver paste over the glass substrate, it caused excessive loss of the silver paste and metal ingredients such as silver required for forming the electrode, leading to a problem of increase in production cost.
Further, as compared to the silver paste method requiring a high temperature sintering process, the plating method includes an etching process instead of the sintering process and can form electrode patterns in a photoresist layer of the substrate without deformation of the substrate and the patterns so that it has an advantage of preventing undercut. However, a wide variety of investigations and studies are now in progressing to solve problems in relation to adhesiveness of the plating pattern to an insulating substrate and plating resistance of the photoresist composition. In other words, the conventional composition for the photoresist had poor plating resistance and a difficulty in forming the metal electrode by means of metal plating process using a strong alkali plating solution with high pH value.
Therefore, it is an object of the present invention to solve the above problems and provide a composition for positive type photoresist which has excellent plating resistance in a metal electrode plating process under the strong alkali condition and is possibly employed in the formation of metal electrode using the metal plating process so that it can greatly reduce loss of metal ingredients such as silver during the formation of the metal electrode, thereby decreasing the production cost thereof, and is useful for forming the metal electrode on the substrate because of superior adhesiveness to the substrate.